Busses, trucks, cars and other motor vehicles have long been used for displaying advertising material. In the most familiar cases, companies owning semi trucks and other vehicles display their corporate logos and slogans or other company information on the vehicles. A less common, but increasingly prevalent example is the use of semis, busses, etc. as mobile road signs. In such applications, the vehicle owner rents space or time, for example, or charges by the mile, to entities that wish their ads to be displayed on the vehicle as it travels. The mobility of motor vehicles allows signs, insignia and other informational media to be conveyed to large, diverse audiences. The painting of signs or application of vinyl graphics on large trucks is well known and widely used, particularly for advertising the goods being transported. However, such signage is relatively permanent and is expensive to change. For trucks dedicated to a single company, painted signs are acceptable and provide a visually stimulating appearance.
A majority of cargo bearing trucks or tractor trailers are not dedicated to a single company or product. Further, many trailers are fungible, mobile storage containers and truck drivers will drop off one trailer at a distribution point and pick up a different trailer for a return trip. Trailers may be left at a distribution point for days and may be used for various goods, different drivers and travel to a number of destinations. Thus, it is impractical to attempt to predict in advance where and when a trailer will be on the road. This lowers the value of placing relatively permanent advertising on a trailer, as the exposure of such advertising is relatively ineffective.
Over the years, there have been various unique contributions to the art, including the addition of electronic signs and symbols, and the use of removable signs mounted in permanent brackets installed on the vehicle itself. One problem that has continually plagued the industry, however, has been the labor and expense involved in retrofitting vehicles with the various fastening and bracketing arrangements that render them capable of supporting the advertising assemblies mounted thereon. In particular, it has proven challenging to design mounting arrangements compatible with the various external features of the vehicle. In the case of semi trailers to which advertising assemblies are to be mounted, fasteners, hinges, external lighting and locks, etc. have heretofore provided impediments in designing suitable advertising systems for mounting on the vehicle. In particular, most trailers have a rear door locking system which includes an elongated bar which engages the top of the trailer thus preventing the prying of the top door edges but is engagable from ground level. This locking system extends several inches from the rear door surface, and complicates applying a flat sign along the rear door surfaces. The dual rear door system of most trailers also complicates the application of signage upon the rear doors. There have been efforts to divide the signage and apply half on each door to meet when the doors are closed.